Investing chamber



Ma-i'ch 17, 1959 5.1, WRIGHT ETAL 2,877,494

Y INVESTING CHAMBER Filed July 20. 1956 .Sy/vqn L. Wright Warren 1.. Wr/gh/ Robert Rees Dans/e mmvrozes INVESTING CHAMBER Sylvan L. Wright, Warren L. Wright, and Robert Rees Dansie, Murray City, Utah Application July 20, 1956, Serial No. 599,140

1 Claim. (Cl. 185.7)

This invention relates to apparatus for investing, under vacuum, dental molds.

An object of the present invention is to provide an apparatus and disclose a technique for investing dental molds with investing material in such manner that the investing material is substantially completely free from water and air without the use of any mechanical mixing device, the latter having been determined to be directly responsible for flaws in the finished product.

A more explicit object of the present invention is to provide an apparatus for filling dental molds with investing material, the apparatus including a preferably cylindrical container having an apertured wall that constitutes the bottom wall of an investment cup socket in which the mold is adapted to be supported in registry with the aperture in the end wall, whereby after being charged with investment material the container is adapted to be tilted to assure free flow of the material into the mold and a vacuum drawn in the air space which remains above the investing material level in the container. Wherefore, due to the resulting bubbling action of the investment material, air and unwanted aqueous vapors are withdrawn from the investment material.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a schematic elevational view of an apparatus which is constructed in accordance with the invention;

Figure 2 is a longitudinal sectional view of the container which constitutes a part of this apparatus.

In the accompanying drawing there is an apparatus which exemplifies the principles of the invention. It consists of a container 12, which may be cylindrical, although other shapes are considered to be possible. Container 12 has a cylindrical side wall 14 together with an end wall 16 and an end wall 18. End wall 18 has an opening 20 in the center thereof through which investment material 22 is adapted to flow. The investment material is commercially available stock or compoundable from commercially available ingredients in common use in the art at the present time.

Investing cup 24 has a cylindrical side wall 26 and a flat bottom 28. Cavity 30 is formed in cup 24 and opens through the bottom 28 thereof. This cavity is adapted to support mold 32 made of wax or other material that is in use at the present time. Mold 32 is to be applied in cup 24 with the mold void facing opening 2,877,494 Patented Mar. 17, 1959 20. Socket 34 is carried by container; 12 and is adapted therein. The socket has a cylindrical side wall 36 of slightly larger diameter than the cylindrical wall 26 of cup 24 and has an inner wall 18 forming the bottom of the socket. Inner wall 18 is common to the socket and to the chamber 40 of the container 14.

A yiedlable gasket 42, preferably in the form of a washer, is interposed between bottom 28 of cup 24 and the outer surface of wall 18. This forms a yielding seat for the cup.

In operation, investment material 22 is applied into chamber 40, gasket 42 placed in the socket 34, and cup 24, having mold 32 in it, is inserted in the socket. The surface 28 of the cup is brought tightly against the gasket 42.

Thereafter, vacuum tube 46 is attached to the nipple 48, the latter being connected to the cylindrical side wall or some other convenient part of the container 14. The vacuum tube is operatively connected to a source of vacuum 50, for example, a vacuum pump or vacuum pump assembly. As the vacuum is drawn in the space which remains above investment 22, the quantity of the charge of investment being restricted in order to leave such an air space when titlted as shown in Figure 2, the investment material 22 commences to boil. The bubbling action while boiling liberates aqueous vapors, air and unwanted moisture from the investment before and while the mold cavity is charged with investment material. Thereafter, the vacuum is broken and the cup 24 removed for further processing in accordance with dental practices.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

An apparatus for investing a dental mold under vacuum without mechanical mixers, said apparatus comprising a container, a socket connected with said container in which to support an investing cup and having a side wall formed as an extension of the side wall of said container said socket having an inner wall common to said container and having an aperture through which the investing material is adapted to pass when the entire container is tilted, a compressible washer in said socket against which the investing cup is adapted to seat, and means communicating with said container for drawing a vacuum in said container in order to purge the container and investing material of moisture and air by bubbling the investment material due to the reduction in pressure above the surface of the investment material.

References Cited in the file of this patent UNITED STATES PATENTS 1,325,044 Davidson Dec. 16, 1919 2,416,506 Vest Feb. 25, 1947 2,457,756 Vest Dec. 28, 1948 2,490,193 Barr Dec. 6, 1949 2,696,022 Steinback et al. Dec. 7, 1954 

